is the oil plug on the drivers side or the passengers side
Start the bike up and let the oil warm up (side of the cylinder should be pretty warm to touch) before killing engine. Remove drain plug (on bottom of engine) and let all oil run out. Replace drain plug and remove filler plug on side of cases and add oil.
It takes about 4.5 quarts if you're changing the filter, which is located on the BACK side of the engine. Drain plug is on the bottom of the engine on the oil pan.
Under the engine on the bottom or side of the oil pan. If you cannot find it then you really have no business changing your own oil. Take it to a professional.
The plug on the same side of the motor that the drive belts is on, which should be the passager side, is the engine oil. The plug on the opposite side is the transmission oil.
The oil plug is on the front left side of the oil pan
If you are talking about the oil drain plug, its pretty much right under the engine, which is slightly to the passenger side front of the car. There is a picture of it along with a complete description of changing the oil, here: http://www.carspace.com/guides/Toyota-Echo-How-to-change-oil
On the oil pan, under the car. If you can't find the drain plug, you have no business changing your own oil.
That depends entirely on the year and model of Harley. Some have the motor oil drain plug under the transmission, some have a plug on the left side of oil tank and some have a hose leading from the right side of oil tank with a plug in its end.
Under the transmission oil reservoir, across from the oil drain plug and on the braking side of the bike. (from bottom of the bike the transmission drain plug will always be on the braking side of the bike. The oil drain plug on the shifting side.)
The oil plug is on the side of the oil pan. On the passenger side of the vehicle. The oil will come squirting out the SIDE of the pan. I could not find the oil plug and when I took the vehicle in for an oil change I insisted on watching the mechanic.
If you look at the back of the transfur case were the drive shaft goes in and you will see a plug on the side towards the bottom. That one is the drain plug, just above it a few inches is the fill plug.
Changing the plugs and plug wires correctly has nothing to do with nor can it cause an oil leak.